17% energy rebate
100% Reduction in Customer Complaints
30% Target Reduction in Energy Consumption Exceeded
“We saved energy and therefore saved money…a lot of money. There have been months where the energy savings made the difference between a profitable versus a loss month. I recommend Save Energy Systems to anyone with a facility with multiple HVAC units. Their response and support have been unparalleled. I can contact them any time and they respond promptly and efficiently, even on weekends. I will be installing the DLC in other facility as my role permits." ~ Joseph Zummo, Director of Engineering, Sheraton Stamford Hotel
The Sheraton Stamford Hotel is a 389 room, full-service hotel with over 18,000 square feet meeting space. There are eighteen water sourced heat pumps ranging in size from 10 to 30 tons that provide heating and cooling to the common areas and conference rooms. The Sheraton Stamford was interested in the Save Energy Systems Demand-Limiting Controller (DLC) to save on their energy costs as well as reduce their energy consumption to be more efficient overall.
Challenge
The hotel experienced extremely high utility bills and very significant discomfort problems because of renovations over the years. Several of the HVAC systems were being controlled by thermostats in the return ducts in the mechanical rooms while others were simply on or off. In addition, several units were controlling areas in the hotel which were competing for service. For example, the lobby and the ball room were on the same unit. During the winter the lobby was cold so wanted heat, but if there was an event in the ball room, it needed cooling. The hotel lost revenue when customers were dissatisfied and either demanded refunds or took their business elsewhere. The hotel had a full-time engineering staff dedicated to trying to keep the lobby and event spaces comfortable, but there were still dozens of complaints every day.
Besides the poor temperature controls in the common areas, the condenser loop which serviced the room heat pumps would occasionally be at the wrong temperature, causing guests to complain about rooms being too hot or too cold. To add insult to injury, the domestic hot water for the guest rooms would also occasionally fail. These issues again created dissatisfied guests who demanded refunds and refused to return to the hotel.
In addition to fixing these issues, the Sheraton Stamford was striving to reach Starwood’s company-wide environmental goal of reducing energy consumption by 30% by 2020. Due to its inability to properly control temperature, the existing system wasted energy by over air-conditioning many areas of the hotel. Energy was also wasted when hotel personnel would forget to turn down thermostats when conference or event rooms were not in use.
Solution
The Sheraton Stamford Hotel enlisted Save Energy Systems to provide customized HVAC controls allowing them to have control of each heat pump, to provide zone comfort, monitor the boilers and reduce high electricity demand charges.
The engineers at Save Energy Systems installed individual DLC controls for zone where the heat pump was exclusive, a Honeywell zone controller for the seven conference rooms and three Emme Room-By-Room systems – which converted what was essentially a three-zone system into a multi-zone system that allowed individual room controls. By time the installation was complete, what was a total lack of control now had 52 control points for HVAC and four monitoring systems for hot water and heat pump condenser loop monitoring.
In order to eliminate high electricity demand charges, the Save Energy Systems DLC server coordinates the activity of all of the hotel’s 18 heat pumps preventing multiple heat pumps from starting up at the same time which, in turn, prevents demand spikes and helps to lower utility demand charges.
Results
- The installation of the DLC system allowed every public room to operate within two degrees of set point while reducing labor costs associated with having hotel engineers trying to manually balance the system on a daily basis
- Customer complaints were completely eliminated
- The heating and cooling set points for each room are now scheduled in advance
- When a room is unoccupied, air conditioning is turned off, greatly reducing energy expense.
- The combined DLC systems qualified for a 17% energy rebate from Eversource, the local electric utility
- Energy saved exceed the 30% target established by corporate, years ahead of the goal.